Hello Processing 2.0 - draw something

It's my first try of using Processing 2.0, to draw something.

void setup() {  // setup() runs once
  size(400, 300);
  background(200);
}
 
void draw() {
  line(0, 0, width, height);
  ellipse(width/2, height/2, 100, 100);
  rect(300, 50, 50, 50);
  rect(300, 150, 50, 50, 10);
}